\psset{unit=0.5,yunit=0.8,algebraic=true, ticksize=-3pt 0,linewidth=0.8pt}
\begin{pspicture*}(-1,-1)(10,10)
\footnotesize
\psaxes[arrows=<->,ticks=none](0,0)(-1,-1)(10,10)
\psplot[linecolor=blue]{0}{3.9}{((x-4)^2+0.5)/(x-4)+5}
\psplot[linecolor=blue]{4.05}{9}{((x-4)^2+0.5)/(x-4)+5}
\psplot[linecolor=red]{0}{9}{x+1}
\psline[linecolor=red](4,0)(4,10)
\psxTick(4){a}
\psyTick(1){b}
\rput[r](10,6){Asíntota oblicua}
\rput[r](10,5){$y=b+cx$}
\rput[l](4.2,1.5){Asíntota vertical}
\rput[l](4.2,0.5){$x=a$}
\end{pspicture*}


